This invention concerns improvements in or relating to fluid injectors.
According to the invention there is provided a fluid injector comprising a liquid supply path to discharge passage means, a liquid return path for liquid supplied through the liquid supply path but not discharged through the discharge passage means, and a gaseous supply path to the discharge passage means and having a region in common with the liquid supply path, by which effecting a variation as between the liquid and gaseous pressures in said region will result in variation in the discharge of liquid from the fluid injector.